Peristaltic rotation pump with exact, especially mechanically linear dosage

ABSTRACT

The peristaltic rotation pump includes the pump segment extending along the working path, which is transversely grooved at the place of contact with the compressed pump segment, and is adjacent along all its length to an elevated circular supporting occlusal path, for rolling of pressure rollers. The working path includes a lead-in path, occlusal path and releasing path. Mechanical linearity of dosing is ensured by a circular occlusal path and the nearly circular releasing path, adjacent along all its length to the elevated supporting occlusal path for rolling of at least three pressure rollers. The angle length of the releasing path corresponding to the distance from the point of the beginning of releasing the pump segment to the point of complete release of the pump segment by the pressure roller is identical with that of the occlusal path.

RELATED U.S. APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO MICROFICHE APPENDIX

Not applicable.

FIELD OF THE INVENTION

The invention deals with a peristaltic rotation pump with exact,mechanically linear dosage, designed particularly for use in medicine,half-operation medicine production and laboratories involved in anysphere.

BACKGROUND OF THE INVENTION

The peristaltic effect is based on the principle of gradual repeatedejection of the dosed media from a flexible container.

Gradual and repeated ejection of the media from the flexible containerhappens on a circular occlusal path by pressing a pressure roller onto aflexible pump segment and simultaneous shifting of the roller in thedirection of the longitudinal axe of the pump segment on the occlusalpath pumps the media.

From the existing approach of all known designs of rotating peristalticrotation pumps in their history it is obvious that the manufacturersonly wanted to reach the pumping effect. All other objective criteria ofpump quality as e.g. accuracy and linearity of dosage were lessimportant as the so far known designs could not meet these qualities inprinciple as they were not able to fix the pump segment on the pumpocclusal path and could not suppress the negative influence of thepressure roller when leaving the pump segment at the output of the pump.

The microprocessor regulation of movement of the pressing element on thepump segment and/or location of the pump segment in line with thegradual pressing by cams perpendicularly on the longitudinal axe of thepump segment represented some kind of improvement. The pump segmentplaced this way is well fixed on the linear occlusal path. As movementof the pressing roller in the direction of the pump segment longitudinalaxe is not applied here, its pre-stressing cannot happen and thuschanges of cross section cannot occur.

Significant reduction of the negative influence of the pressing elementwhen leaving the pump segment on the output of the pump is nottechnically solved by this design solution either.

The most progressive known design so far solves the mechanical drawbackof lack of dosing linearity and accuracy by microprocessor regulation ofnon linear movement of pressure rollers (pressure elements in general)both in one pumping cycle and more pumping cycles. Higher dosageaccuracy and linearity can be achieved this way when the smallest doseof the pump (which is usually an integer multiple of the smallest volumeejected by one cycle) is specified, but only for bigger dosage volumes.

Non linear regulation in this instance means different speed of thepressure roller (pressure element in general) in different sections ofthe pump segment of one pumping cycle, the aim of which is to compensatemechanical non linearity of the chosen pump design by its oppositeinfluence.

Mechanical non-linearity of pumping in one pumping cycle is primarilycaused by cyclical constriction (pressing) of the pump segment at thebeginning of the occlusal path, which ejects a non-zero volume from thepump segment, and secondarily by cyclical release of the pump segmentafter the end of the occlusal path, which causes expansion of theflexible pumping segment and thus reception of the above mentionednon-zero disturbing volume (V_(DISTURBING)), causing pulsing of thepumped media and one-revolution non linearity of the dosed media at thepump output.

BRIEF SUMMARY OF THE INVENTION

The principal drawbacks of peristaltic rotation pumps, i.e. overallsubstantial inaccuracy of pumping and pulsing of the pumped media on thepump output during one revolution of the pump rotor are removed by theperistaltic rotation pump for exact dosing comprising of a pump segmentlocated on a working path, and a rotor with pressure rollers, which isaccording to the invention based on the fact that the pump segment isextended to the working path, which is transversely grooved at the placeof touch with the pressed pump segment, and is adjacent within its alllength to an elevated circular supporting occlusal path for rolling atleast two pressure rollers which are sliding mounted in pressing blockslocated in the arms of at least double-arm rotor connected with a shaftof a stepping motor, while the supporting occlusal path is elevated inthe central direction over the transversally grooved working path, whichconsists of a lead-in path, occlusal path and releasing path.

The pump segment is extended in the working path and both the ends ofthe pump segment are leant outside the working path on a supportingsurface, and the pump segment forms angle a 90° with the working pathradius at the point of the pump segment diversion from the working path.

Mechanical linearity of dosing is ensured by the circular occlusal pathand approximately circular releasing path adjacent within all its lengthwith an elevated circular supporting occlusal path for rolling of atleast of three pressure rollers. The angular length of the releasingpath, corresponding with the distance from the beginning of releasing ofthe pump segment to the point of complete release—it means nothing forceby the pressure roller on the pump segment, is the same as the angularlength of the occlusal path and the supporting occlusal path is elevatedabove the occlusal path by the distance d<double of thickness of thepump segment wall and at the point of complete release of the pumpsegment the supporting occlusal path is elevated above the releasingpath by the distance k, which is maximum the same as the externaldiameter of the pump segment.

The rotor is made of at least double-arm hollow profile in which thewhole inside space of each hollow profiled arm contains a pressureblock, each of them is divided by a longitudinal partition into twoparts, a spring is located in each of the parts, the pressure blocks aresecured in each arm of the hollow profile of the rotor within the lengthof their strokes by a pin placed in the lengthwise partition of thepressure block and moves in the first groove made in the arm of thehollow profile, the springs inside the pressure block are leant againstthe back wall of the sliding mounting, in which a roller is freelylocated from the other side, the springs are pre-stressed at the otherend against the body located in the center of the hollow profile, thebody is fixed with a locking close to the stepping motor shaft, the bodyis at least a trilateral prism.

For a double-arm rotor the body is a quadrilateral prism.

For a three-arm rotor the body is a trilateral prism the roundedvertexes of which mesh into the second socket at the place of connectionof the hollow profile arms. The body is fitted with a protrusion on thefront side, in which a locking spring is located, a locking groove andan inlet groove for the locking pin placed on the shaft are on the backside of the body, the width of locking groove in the most distantposition is narrower, that the diameter of the locking pin.

The pin of the pressure block fits into the first groove symmetricallylocated in the front part of the hollow profile of the rotor, the pinlocks at the same time into the appropriate second groove of the controlelement designed for handling the pressure block when locating to rotorto the working path, into which the pump segment is pressed byexpansion. The control element is connected to a cylindrical extrusionby thread.

The minimum length of the occlusal path is defined by the size of thecentral angle of the pump rotor rotation and is calculated as360°/number of rotor arms.

The pressure block is equipped with guiding grooves for transversalguiding of the pump segment on the grooved working path.

The pressure roller is a roller from a roller bearing, which slides withthe whole cylindrical surface in the sliding mounting of the pressureblock.

The sliding mounting is finished with wiping blades for removing ofpossible dirt in both directions of rotation, there are sockets in thehead of the pressure block at the level of the wiping blades.

The stroke length of the pressure block moves between 1.1 to 2.0multiple of the pump segment external diameter.

The pressure roller is an electric conductor and when it touched thespeed contact or the position contact located on the supporting occlusalpath at the point of the change from the lead-in path into the occlusalpath, and with a common contact located against them on the edge of theocclusal path, is under electric current of very low voltage.

The pressure roller may also be magnetized.

By expansion of the pump segment and its leading on an arch of radius ofabout three to four times the radius of the occlusal path and by leaningof the ends of the pump segment against the supporting surfaces thebasic radial pressure of the pump segment against the transversallygrooved working path of the pump is into being. The pump segment lengthhas to be by 2-5 percent longer than the distance between the supportingsurfaces of the pump segment in the pump box case measured on theworking path perimeter. The rate of “compression” of the length isadequate to the pump segment diameter and the thickness of its wall. Thepump segment has to be in the plane perpendicular to the main rotationaxe of the pump even after pre-stressing of its length. Thepre-stressing causes the basic forces pressing the pump segment to theocclusal path.

Lengthwise shifting of the pump segment on the working path of the pumpin the direction of the rotor rotation is prevented by transversalgrooving of the working path. The basic pressure forces the soft surfaceof the pump segment into the transversal grooves even when the pump isswitched off, and then, when it is on the pressure roller moving on thepump section in longitudinal direction even increases this impression inthe contact point.

The transversal cross section through the grooving has an advantageousshape of isosceles triangle of height between approx. 0.15 and 0.50 mm,depending on the pump segment radius and thickness of its wall.

Transfer of the excessive compressing force of the pressure roller tothe supporting occlusal path prevents crushing and occurrence ofundesirable or even harmful force causing through the movement of thepressure roller lengthwise movement of the pump segment, when thegrooved occlusal path is smooth or worn out.

The pressure roller leaning also on the supporting occlusal path thencannot crush the pump segment by excessive force. It either cannot sinkdeeply in the soft pump segment by excessive force and thus generate anundesirable shifting force applied on the pump segment in the directionof its longitudinal axe (length).

The level of the pressure force of the pressure roller is adjustedautomatically for variable working conditions of the pump byredistribution of the total pressure force between the grooved workingpath with inserted pump segment and the supporting occlusal path. Thedistance between the occlusal path and the supporting path has to beshorter by the manufacturing tolerance of the pumping segment than thedouble thickness of the wall of the pump segment.

The fixed distance of the supporting occlusal path from thetransversally grooved working path defines the extent of clasp of thepump segment on the occlusal path and the releasing path for releasingof the pump segment from the occlusal path and thus also the volumeejected by the pressure roller from the pump segment only as a result ofits radial application on the pump segment.

The source of pulsing (i.e. repeated releases of the compressed flexiblecontainer) cannot be removed, the consequences, i.e. the cyclical dropand increase of the ejected medium (pulsing) at the pump outlet in onecycle period can be removed mechanically, if the mutually correctcorrelation of geometrical dimensions is observed, i.e.

-   -   equal lengths of the occlusal path and the releasing path for        the guiding of the pump segment from the occlusal path; and    -   constant increment of the pump segment volume at gradual release        of the pressure of the pressure roller on the releasing path        related to any unit of its length regardless the chosen way of        mechanical clasp of the pump segment.

Mechanical linearity of the peristaltic rotation pump according to theinvention is ensured by the equal angle lengths of the occlusal and thereleasing paths. This condition can only be met with a three-or more-armpump rotor.

The pump rotor arms have to be symmetrically situated in a circle, i.e.in the angle of 360°. The minimum length of the main occlusal path ofthe pump in angle degrees is defined from the formula 360°/number of thepump rotor arms. FIG. 1A shows location of the of the decisive parts ofthe pump in the pump case for three-arm rotor. The minimum length of themain occlusal path of the three-arm pump rotor is thus defined by thecentral angle 120°, which can be extended by angle β at the sucking partof the pump. The length of guiding the pump segment from the occlusalpath has to be exactly 120° of central angle of the pump rotor swing fora three-arm rotor, as it ensures mutually continuous linkage of eachpump rotor arm cycle to the next one.

For a four arm rotor the basic central angle of the arms is 90°, for afive-arm rotor 72° and, for six arms it is 60°, etc.

With zero back pressure at the pump output only minimum pressure of thepressure roller is sufficient for closing the pump segment cross sectionand the excessive force of the pressing springs is compensated byreaction of the supporting occlusal path on which the pressure rolleralso rolls. When the back pressure increases the need to increase thepressing force of the pressure roller increases. This happensautomatically by reduction of the force applied by the same pressureroller on the supporting occlusal path.

The pressure roller of any of the pump rotor arms rolls on thesupporting occlusal path and at the place of concurrence also on thepump segment placed in the working path. The pressing force of theroller is carried out by the sliding mounting of its surface in thepressure block. It is thus a unique combination of rolling and slidingfriction of the pressure roller of the peristaltic rotation pump out ofthe rotation axe of the pressure roller. This holds the reaction ofpressing force of the pressure roller in the sliding mounting in thepressure block of the pump rotor.

Positioning of the pump rotor in the pump case without dislocation ofthe pump segment on the working path is a substantive condition forreaching high pumping accuracy. The design of the hollow profile of thepump rotor, in the arms of which the pressure blocks move, enables touse the design space thus created for the biggest possible diameter,length and number of threads of spiral pressing springs. This ensureshigh stroke of the pressure roller and the softest possiblecharacteristic of the pressing force, i.e. condition closest to therequirement, that the change of the pressing force of the pressureroller is approximately constant for the pressure block stroke.

When putting the pump rotor into the pump case with the pump segmentalready fitted it is necessary to avoid wrong displacement of the pumpsegment from the working path to the supporting occlusal path. It isensured by simultaneous high stroke of all pressure rollers when puttingthe rotor in and by groove guiding of the pump segment in transversedirection in all the pressure blocks for both direction of the pumprotor rotation.

Easily disconnectable fixing of the pump rotor on the propulsive shaftof the step motor with self-adjusting clearance of the angle deviationin both directions of the rotor rotation is ensured by a locking close.

You turn the pump rotor placed on the beginning of the shaft so as theinput groove for the locking pin is parallel with the locking pin on theshaft. You get over the back pressure of the locking spring locatedinside the body of the rotor hollow profile and after pressing to thelimit position you turn the rotor by specific angle of approx. 30°-45°.When you release the pressing force gradually the locking pin locks intothe groove. To dismantle the rotor proceed in reverse mode.

The locking groove has the same or less width in the limit position thanthe diameter of the locking pin is. This ensures permanent definition ofthe clearance by permanent pressing the locking pin into the groove bythe pressing spring force during operation and even when the unit isworn out.

The torque of the step motor is transferred via the locking pin on theshaft and via the locking groove in the pump rotor body.

The peristaltic rotation pump is usually located in a case and the motoroperation is controlled by a microprocessor or by a computer.

Accuracy of the peristaltic pump according to the invention achieves,and in numerous applications even outmatches accuracy and linearity ofso far known alternative means of discrete and continuous dosage, and isdetermined by:

-   -   1) Long-term and stable fixation of the pump segment on the        working path of the pump.    -   2) exactly defined distance between the pressure roller and the        pump segment at each point of the pump working path.    -   3) Mechanical split of the working path of the pump into two        paths of identical length, i.e.    -   a) occlusal path of the pump; and    -   b) releasing path for guiding the pump segment out of the        occlusal path of the pump, and lead-in path of any length for        guiding the pump segment into the occlusal path of the pump.        These three paths form the working path of the pump segment of        each pump.    -   4) Mechanically provided constant increment of the pump segment        volume by gradual releasing of the pressure roller from the pump        segment located by the release path for leading the pump segment        out of the occlusal path.

Pumping linearity is ensured by removal of negative influence of thatparticular pressure roller, which is moving on the pump segment at theoutput from the occlusal path of the pump. Accuracy and long-termstability of the pump mechanical function then enables furthersubstantial increase of dosage accuracy by microprocessor calibrationfor individually used pump segment.

The peristaltic rotation pump according to the invention is a seriesmanufacturable product with tiny and also definite (i.e. not random)dispersion of functional parameters of one particular pump. It has anexact linear dependence of dosed volume on the number of steps (theangle of the rotor movement) of the pump.

This applies until occurrence of irreversible deformation of the pumpsegment not replaced by the user despite highlighted manufacturer'swarning in the operation manual.

The linear dependence of the dosing volume on the number of steps (rotormovement angle) obtainable in practice enables usage of softwarecorrection of the accuracy of the dosed volume for any chosen dosewithin individual calibration of a particular pump segment used, andthus increase substantially the accuracy range of the whole unit for adeclared pumping dose.

The peristaltic rotation pump with exact dosage has the followingadvantages against the previous solutions:

-   -   A) The pump is exact and mechanically linear from the design        principle and these features are not substantially dependent on        manufacturing tolerances of the individual mechanical        components.    -   B) Linear dependence of the dosed volume on the number of steps        (angle of rotor rotation) of the pump is an indisputable        advantage.    -   C) The pump is also cheap to manufacture and does not require        specialist installation and mechanical calibration in        manufacturing, non-observance of which might cause later        accuracy of the unit.    -   D) It is a maintenance free device for the whole life period and        the operation is simple. It only requires a few-minute training        how to put the pump segment and the rotor into the pump case.    -   E) the wide range of pumping parameters ranging from microliters        to tens or hundreds of liters may be covered by just one or two        design variations of the pump.    -   F) It may be switched during operation by a control to both        directions of rotation with no change in accuracy and linearity        of pumping, i.e. it can be used as a compressing or suction        pump. It is similar to sucking of medicine by an injection        syringe and subsequent injection of the medicine into a        patient's body.    -   G) Liquids as well as gases may be pumped and dosed with the        same accuracy.    -   H) The dosage accuracy achieved with low costs may also be used        in highly pure environment by using sterile sets, e.g. dosage of        medicine by infusion pumps, dosage pumps operating in laminate        boxes, laboratory distributors for small-series production, half        operating medicine production etc.    -   I) The low manufacturing costs with reaching the declared        accuracy enable the pumps to be also used where the accuracy is        not the decisive parameter (supplying nutrition in the digestion        system, endoscopic operation of nee arthritis, sucking liquids        from operation wounds, dialyse monitors etc.).

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1A shows schematically the rotation pump case with the pump segmentand the rotor inside.

FIG. 1 b shows a detail of the occlusal path start

FIG. 2 shows an axonometric view of the dismantled pump

FIG. 3 a shows an axonometric view of the rotor from the front.

FIG. 3 b shows an axonometric view of the rotor from the rear.

FIG. 4 shows dismantled rotor system.

FIG. 5 a shows the rotor three lateral from the front.

FIG. 5 b shows the rotor three lateral from the rear.

FIG. 6 a shows the pressure block from the front.

FIG. 6 b shows the pressure block from the rear.

DETAILED DESCRIPTION OF THE INVENTION

The peristaltic pump for exact dosing consists of the pump segment 1 ofexternal diameter 3.9 mm placed on the working path 24 of diameterapprox. 65 mm and three-arm rotor 6 with pressure rollers 4. The pumpsegment 1 is from an infusion set normally available in medicine. Theworking path 2 is transversally grooved at the place of contact with thecompressed pump segment 1, and is adjacent and is adjacent along thewhole perimeter to the elevated supporting occlusal path 3, on whichthree pressure rollers 4 roll, sliding mounted in pressure blocks 5fitted in arms 23 of the rotor 6. The pressure roller 4 is a roll from arolling bearing of diameter 9 mm, made of hardened and lapped steel. Therotor 6 is made of a three-arm hollow profile 7, in which the wholehollow of the arms 23 is filled with three symmetrically locatedpressure blocks 5, in each of which springs 8 are located, separated bya longitudinal partition 13. The springs are pre-stressed against thebody 22 placed in the hollow profile 7. The body 22 is a three lateralprism the rounded corners 35 of which fit into the second socket 34 atthe place of connection of the arms 23 of the hollow profile 7, the body22 has a cylindrical protrusion 29 at the front, on which a securingspring 17 is placed, a securing groove 19 is made in the back side ofthe body 22 and input groove 20 for securing pin 21 placed on the shaft9 of the motor 10. The width of the securing groove 19 at the mostdistant position is narrower than the diameter of the securing pin 21is.

The pump segment 1 is mechanically compressed to the working path 24,which consists of the lead-in path 15, occlusal path 2 and releasingpath 16.

Both ends of the pump segment 1 lean against the supporting surface 18.

The supporting occlusal path 3 is elevated above the grooved occlusalpath 2 by the distance d=1.0 mm.

The pressure block 5 is provided with a guiding groove 111 fortransversal guiding of the pump segment 1 on the grooved working path24.

The stroke of the pressure block 5 is 7 mm, which is in the range of 1.1to 2.0 multiple of the external diameter of the pump segment 1.

The pressure blocks 5 are secured inside the rotor 6 within the range ofthe stroke with a pin 12 placed in the front on the longitudinalpartition 13 placed in the pressure block 5. The pin 12 locks into thefirst grooves 14 symmetrically located inside the hollow profile 7 ofthe rotor 6 and at the same time into the appropriate second groove 33of the control element 32 designed for handling the pressure blocks 5when the rotor 6 is being mounted to the working path 24 into which thepump segment 1 is pressed by expansion, the control element 32 isconnected to the cylindrical protrusion 29 by thread.

The length of the grooves 14 is 7 mm+0.8 mm for the securing pin 12. Therotor 6 is connected by the body 22 to the shaft 9 of the step motor 10by a locking close secured by a securing spring 17.

The pressure roller (4) is an electric conductor and when it touches thespeed contact (25) or the position contact (26) located on thesupporting occlusal path (3) at the point of the change from the lead-inpath (15) into the occlusal path (2), and with a common contact (27)located against them on the edge of the occlusal path (2), is underelectric current of very low voltage.

To prevent unintentional rotation of the control element 32 duringoperation of the pump, there are depressions 30 to which protrusions 31placed on the front side of the hollow profile lock 7.

Description of the Function

1) Before Commissioning

You shift the pump segment 1 with its solid ends into the holders of thepump case equipped with supporting surfaces 18. After that you press therest of the pump segment 1 to the grooved working path so as the pumpsegment 1 covers the lead-in path 15, the occlusal path 2 and thereleasing path 16 at the same distance from the edge of the supportingocclusal path 3.

You shift the pressure blocks 5 into the arms 23 of the hollow profile 7by means of the control element 32 and the rotor 6 is ready for freesliding into the pump case. You turn the input groove 20 in the body 22of the rotor 6 parallel with the locking pin 21 placed on the shaft 9 ofthe step motor 10 and slide the rotor 6 on the shaft 9, you press itagainst the securing spring 17, turn right by 30°; after that yourelease the pressure against the rotor 6. The pin 21 of the shaft 9 ofthe stepping motor 10 then locks in the securing groove 19 in the body22 and the motor 10 is connected to the rotor 6 without any play.

When you turn the control element 32 back, the pressure blocks 5 slideout of the rotor 6 hollow profiles 7 arms 23, and the pressure rollers 4lean against the supporting occlusal path 3 and also against the pumpsegment 1 located on the working path 24. At the same time the guidinggrooves 11 of the pressure blocks 5 are ready to guide the pump segment1 transversally on the working path 24.

With each switching on and without using the pumped medium the unitcarries out an automatic functionality self-check via the electricposition contact 26, which senses position of the pump rotor 6. Byrotation of the rotor 6 with the pump segment 1 inserted any of thepressure rollers 4 rolls on the electric position contact 26 and thecommon contact 27 and causes their conductive connection. The electronicsystem immediately and with high angle accuracy determines the number ofsteps of the stepping motor necessary to repeated turn of the rotor 6.To switching the same electric contact by the pressure roller of anyfurther arm in any direction, and the electronic system carries out thetest. The unit thus tests correct operation plays of all moving parts ofthe pump rotor 6 as well as accuracy of adjustment of the pressing forceof the pressing springs 8.

The pump is thus able to determine the condition when it can or cannotensure the correctness and accuracy of pumping.

2) Pumping

You place the input hose fitted to the pump segment 1 into a vessel withthe pumped medium, and the output hose, also fitted to the pump segment1 into the vessel you want to dose the medium into.

After switching the unit on you fill the pump system (the hoses)completely by electric rotation of the rotor 6. Then you adjust thevolume to be dosed, which will be automatically calculated into thenecessary number of steps of the stepping motor 10. After pressing theStart button the rotor 6 of the pump starts turning and the programmedexact and linear pumping starts.

The pressure roller 4 of one of the rotor 6 arms 23, which moves on thesupporting occlusal path 3 between the input and output hoses, when therotor 6 turns, starts to press the pump segment 1 and thus reduce itscross section. Complete compression of the pump segment 1 by thepressure roller 4 always occurs at the most distant point 28 of theprolongation of minimum length of the main occlusal path, when the rotor6 turns slowly.

When the rotor 6 rotation velocity increases, with higher viscosity ofthe pumped medium or with pumping against back pressure the rightcompression of the pressure roller 4 occurs, later in the direction ofthe pump rotor 6 rotation. At the rotor 6 speed, when the pressureroller does not connect the electric speed contact 25 with the commoncontact 27, the electronic system interprets the speed as too high andslows down the rotation speed accordingly. Then the connection of theposition contact 26 (located by approx. 4° in the direction of the rotor6 rotation in relation to the contact 25) with the common contact 27 hasto occur, which defines the beginning of the occlusal path 2 andreliability of the compression of the pressure roller for any rotationspeed of the rotor 6, and thus pumping correctness and liability. Thepump in this operation mode of maximum pumping speeds then guaranteescorrect compression of the pump segment 1 at the beginning of theocclusal path 2 and thus also the accuracy of pumping. Reading ofrotation speed and also the position of the rotor 6 happens 3 times perrevolution for a three-arm rotor, and so the regulation loop is quitestable at this speed range.

The pump is thus able to determine and not to exceed the maximum pumpingspeed, at which it still can guarantee correctness and accuracy ofpumping even under variable operation conditions.

At the moment of compression of one of the pressure rollers 4 on thepump segment 1 and also on the electric position contact 26 thepreceding pressure roller 4 is at the end of the occlusal path 2 and atthe beginning of the releasing path 16.

Further slight turn of the rotor 6 shifts the above mentioned precedingpressure roller 4 to the releasing path 16, which causes opening thepump segment 1, tightly closed before that, by constant volume. Eachfurther movement of the rotor 6 causes progressive release of thepressure roller 4 from the pump segment 1 by constant volume, which issupported by the transversally grooved releasing path 16. A relationgeometrically unequivocally and repeatably defined between thesupporting occlusal path 3 and the releasing path 16 by a constantvolume increment of the pump segment 1 being released, related to theunitary angle of rotation of the pump rotor 6.

The pumped medium is forced out of the pump segment 1 and thus also outof the pump output by the pressure roller 4, which is moving at thatmoment on the part of the pump segment 1 adjacent to the occlusal path2. The preceding pressure roller 4, which is moving on the pumpingsegment I adjacent to the releasing path 16, does not influence thepressure force of the pump, as the space inside pump segment 1 beforeand after this roller 4 is then connected and gradually filled with themedium forced by the next roller 4 moving on the pump segment I on theocclusal path 2. The above algorithm still repeating after each 120° ofthe three-arm pump rotor turn (or each 90° with 4-arm rotor, 72° with5-arm rotor, 60° with 6-arm pump rotor etc.) really compensates theinfluence of the pressure roller moving on the pump output.

3) After Pumping

The unit switches off.

By turning the control element 32 of the rotor 6 the pressure blocks 5slide inside the arms 23 of the hollow profile 7 of the rotor 6. Axialpressure on the rotor 6 causes higher compression of the spring 17fitted in the hollow cylindrical protrusion 29 of the body 22 againstthe shaft (9) of the motor 10, and the securing pin 21 gets out of thesecuring groove 19. By turning the rotor to the left the securing pin 21moves opposite the output groove 20 and the rotor 6 may be pulled of theshaft 9 of the motor 10. By turning the control element 32 in theopposite direction the pressure blocks 5 slide out and their pressingsprings 8 get partly released.

You pull the pump segment 1 out of the space of the working path 24 andthen out of the other space. Finally you remove the ends of the pumpsegment supported by the supporting surfaces 18.

Industrial Application

The peristaltic pump according to the invention is applicable anywhere,where accuracy of dosage of liquids or gases is required. It isespecially designed for application in medicine and in chemical,physical or biological laboratories.

1. A peristaltic rotation pump with exact, especially mechanicallylinear dosing, comprises: a pump segment placed on a working path, issaid path being adjacent to an elevated circular supporting occlusalpath and a rotor with pressure rollers, characteristic by the fact, saidpump segment extending along the working path, both ends of said pumpsegment leaning against a supporting surface outside the working path,the working path being transversally grooved at the place of contactwith the compressed pump segment and being adjacent within all itslength to an elevated circular supporting occlusal path on which atleast two pressure rollers roll, the rollers being freely slidingmounted with their outside surface in a hollow slide mounting of thepressure blocks placed flexibly in the hollow arms of at leastdouble-arm rotor, the rotor being connected to a shaft of the stepmotor, while the supporting occlusal path is elevated in the directionto the rotor rotation center above the transversally grooved workingpath comprised of the lead-in path, occlusal path and releasing path. 2.The peristaltic pump according to claim 1 the wherein said pump segmentforms angle α=90° with the radius of said working path at the point ofdiversion of the pump segment from the working path.
 3. The peristalticpump according to claim 1, wherein the circular occlusal path and nearlycircular releasing path are adjacent to an elevated circular supportingocclusal path along a whole length thereof, for rolling of at leastthree pressure rollers, and elevating the supporting occlusal path abovethe occlusal path by distance d<than twice the width of the pump segmentwall, and at the point of absolute release of the pump segment, thesupporting occlusal path being elevated above the releasing path by adistance less or equal to the external diameter of the pump segment,while the angle length of the occlusal path equals to the angle lengthof the releasing path corresponding to the distance from the point wherethe pressure roller starts releasing the pump segment to the point ofcomplete release of the pump segment by the pressure roller, where thepressing force of the pressing roller to the pump segment is zero. 4.The peristaltic pump according to claim 1, wherein the rotor comprising:at least a two-arm hollow profiles an inside space of each arm of eachhollow profile being filled with a pressure block, each profile beingsplit by a longitudinal partition into two parts; a spring placed ineach part, the pressure blocks being secured in each arm of each hollowprofile within an extent of stroke thereof by a pin located in alongitudinal groove of the pressure block and going through the firstgroove made in the arm of the hollow profile, each spring being leantinside the pressure block against the back wall of the slide mounting;and a freely located a roller, each spring being pre-stressed at theother end against the body located in the hollow profile, the body beingfixed by a bayonet close to the shaft of the step motor, the body beingat least trilateral prism.
 5. The peristaltic pump according to claim 1,wherein the rotor has two arms and wherein the body is a tetralateralprism.
 6. The peristaltic pump according to claim 1 wherein the rotorhas three arms, wherein the body is a trilateral prism, the roundedcorners thereof fitting into the second socket at the place ofconnection of the arms of the hollow profile, the front of the bodybeing fitted with a cylindrical protrusions, in which a securing springis placed, wherein the back of the body has a securing groove and aninput groove for a securing pin placed on the shaft, the width of thesecuring groove at its most distant point from the cylindricalprotrusion axis being less than the diameter of the securing pin, andwherein a pin of the pressure block fits into the first groovesymmetrically placed at the front of the rotor and hollow profile, thepin locking at the same time into the appropriate second groove of thecontrol element handling the pressure blocks when the rotor is insertedinto the working path, into which the pump segment is pressed byexpansion, the control element being connected by thread with thecylindrical protrusion.
 7. The peristaltic pump according to claim 1,wherein a minimum length of the occlusal path is defined by size of acentral angle of the rotor rotation and is calculated from the formula360°/number of arms of the rotor.
 8. The peristaltic pump according toclaim 1, wherein said pressure block is comprised of guiding grooves fortransversal guiding of the pump segment for the grooved occlusal path.9. The peristaltic pump according to claim 1, wherein the pressureroller is a roll from a rolling bearing which slides by all cylindricalsurfaces thereof in sliding mounting of the pressure block.
 10. Theperistaltic pump according to claim 1, wherein the sliding mounting isfinished with wiper blades for removing possible dirt in both directionof rotation of the rotor, and wherein sockets are made on the head ofthe pressure block at the level of the blades.
 11. The peristaltic pumpaccording to claim 1, wherein a length of stroke of the pressing blockmoves in the range of 1.1 to 2.0 multiple of the external diameter ofthe pump segment.
 12. The peristaltic pump according to claim 1, whereinthe pressure roller is an electric conductor and when it gets totouching a speed contact or the position contact located on thesupporting occlusal path where the lead-in path changes into theocclusal path and with common contact placed opposite to them on theedge of the occlusal path, the conductor is under electric current ofvery low voltage.
 13. The peristaltic pump according to claim 1, whereinthe pressure roller is magnetized.